Mouse models of human disease have provided essential insights into renal pathophysiological processes and are an important preclinical resource to test therapeutic and preventive approaches in acute kidney injury (AKI). The specific aims of Core B are to provide the facilities and requisite skills 1) to study murine models of AKI, 2) for small animal imaging, and 3) to determine renal physiological changes in AKI. This core will specifically provide (i) expertise in development and training in the use of rodent models of AKI specifically in the setting of ischemia/reperfusion injury, sepsis and renal transplantation, (ii) a multi-modality small animal imaging core that will provide state-of-the-art molecular imaging, including functional, structural and metabolic imaging using magnetic resonance imaging/spectroscopy, high frequency ultrasonography, microCT, gamma-ray imaging (gamma camera, microSPECT/CT, microPET/CT), and optical imaging (bioluminescence and fluorescence), and (iii) a physiology core that will provide expertise and training for studying renal function on the whole kidney and at the single nephron level, including micropuncture techniques and determination of GFR, microanalysis of tubular fluid and tubular reabsorption, renal hemodynamics with assessment of tubuloglomerular feedback, and metabolic assessment of kidney oxygen consumption in rodents. Core B will also provide technical expertise for the isolation of primary renal and vascular cells in culture from rodents. The intent of Core B is to provide unique resources that help overcome barriers for investigators to utilize relevant rodent models for in vivo studies and rodent cell lines for in vitro studies to advance understanding of the pathophysiology of AKI. Core B has been very successful in supporting the kidney research community. Since the inception of Core B, more than 5,800 procedures have been performed for 80 principal investigators involving 92 projects. Of the 80 investigators, 60 (75%) were non-core personnel. The number of investigators using Core B each year is increasing, as is the annual publication rate. Core B has also supported the research efforts of 11 Pilot and Feasibility grant awardees. These combined efforts have been currently recognized in 83 peer-reviewed publications. The sophisticated infrastructure coupled with the unique expertise of Core B will continue to catalyze collaborative efforts between and UCSD and produce innovative new initiatives that will advance AKI research.